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<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script type="text/javascript">

    let data = {
        name:'尚硅谷',
        address:'北京',
    
    }

    //创建一个监视的实例对象用于监视data中的属性变化
    const obs = new Observer(data)
    console.log(obs)
    //准备一个vm实例
    const vm = {};
    vm._data = data = obs;

    function Observer(obj){
        //汇总对象中所有的属性形成一个数组
        const keys = Object.keys(obj)
        //遍历
        keys.forEach((k)=>{
            Object.defineProperty(this,k,{
                get(){
                    return obj[k];
                },
                set(val){
                    console.log(`${k}被改了,我要去解析模板 生成虚拟dom 我要开始忙了`)
                    obj[k] = val;
                }
            })
        })
    }
    </script>
    
</body>
</html>